collectd/dhcpcount: properly calculate timeout

salt/collectd/collectd.conf

@@ -35,9 +35,17 @@ LoadPlugin ping
 </Plugin>
 
 {%- elif plugin == 'dhcpcount' and conf %}
+{%-   set timeout = 60 %}
+{%-   for iface, ips in salt['grains.get']('ip_interfaces').items() %}
+{%-     set dhcp_conf = pillar['dhcp'].get(iface) %}
+{%-     if dhcp_conf and dhcp_conf.get('time') and dhcp_conf.get('time') > timeout %}
+{%-       set timeout = dhcp_conf['time'] %}
+{%-     endif %}
+{%-   endfor %}
+
 LoadPlugin exec
 <Plugin exec>
-  Exec "nobody" "/usr/bin/dhcpcount.rb"
+  Exec "nobody" "/usr/bin/dhcpcount.rb" "{{ timeout }}"
 </Plugin>
 
 {%- elif conf is mapping %}

salt/collectd/dhcpcount.rb

@@ -3,6 +3,7 @@
 require 'date'
 
 INTERVAL = 10
+TIMEOUT = ARGV[0].to_i
 hostname = `hostname`.strip
 STDOUT.sync = true
 
@@ -12,22 +13,18 @@ loop do
 
   addr = nil
   starts = nil
-  ends = nil
 
   IO::readlines("/var/lib/dhcp/dhcpd.leases").each do |line|
     if line =~ /^lease (.+) \{/
       addr = $1
 
       starts = nil
-      ends = nil
     elsif line =~ /starts \d+ (.+?);/
-      starts = DateTime.parse $1
-    elsif line =~ /ends \d+ (.+?);/
-      ends = DateTime.parse $1
+      starts = DateTime.parse($1).to_time
     elsif line =~ /^\}/
-      now = DateTime.now
-      if starts and ends and
-         starts <= now and ends >= now and
+      now = Time.now
+      if starts and
+         now >= starts and now < starts + TIMEOUT
 
         unless seen[addr]
           count += 1